import React, { Component } from 'react';
import './index.css'
class Footer extends Component {
  
  handleCheckAll = (event)=>{
    this.props.checkAllTodo(event.target.checked);
  } 
  handleClearAllDone = ()=>{
    const {clearAllDone} = this.props;
    clearAllDone();
  }
  render() {
    const {todos} = this.props
    //已完成的个数
    const doneCount = todos.reduce((pre,todo)=>{
      return pre + (todo.done?1:0)
    },0)
    //总数
    const total = todos.length
    return (
      <div className="todo-footer">
        <label>
          <input type="checkbox" onChange={this.handleCheckAll} checked={doneCount===total && total !== 0 ? true : false}/>
        </label>
        <span>
          <span>已完成{doneCount}</span> / 全部{total}
        </span>
        <button onClick={this.handleClearAllDone} className="btn btn-danger">清除已完成任务</button>
      </div>
);
  }
}

export default Footer;